1. Field of the Invention
This invention generally relates to an electronic musical instrument, and more particularly, to a motif performing apparatus for automatically performing motifs or motifs. Note, the term "motif" as used herein refers to a basic element which includes several pitches or rhythms, is repeatedly used during a performance of a piece of music, and includes a phrase or period or a plurality of phrases or periods.
2. Description of the Related Art
An electronic musical instrument having an automatic accompaniment function, i.e., automatically providing an accompaniment is widely known. Namely, when performing a piece of music, such an electronic musical instrument first provides an automatical rhythm backing function, then, when an accompaniment key is operated, a chord assigned to the accompaniment key is sounded; a root thereof being connected with the automatic rhythm backing. Note, a chord comprises three or more pitches sounded simultaneously, and a root thereof is a fundamental pitch of the pitches composing a chord. In some cases, chord composing pitches other than the root of a chord may be simultaneously sounded when playing the chord.
Further, there is known another electronic musical instrument in which the rhythm backing is provided by using a keyboard. In this case, each of the instrumental parts (e.g., drum and cymbals parts) for playing the rhythm backing is assigned to a corresponding key on the keyboard, and in response to a "KEY ON" operation (i.e., an operation of pressing down one of the keys to play a note), the sound of the corresponding instrumental part is generated.
Furthermore, in still another well-known electronic musical instrument which automatically performs melodies, data of melodic patterns is prestored, and when performing a piece of music, the stored data is read out when a switch is pressed to start the automatic performance of the melody, and thereafter, musical tones corresponding to the read data are sequentially generated.
These conventional electronic musical instruments, however, have the drawbacks as described hereinbelow.
First, in the case of the above described electronic musical instrument having the automatic accompaniment function, a chord which includes a root and is assigned to an accompaniment key cannot be changed, and thus whenever the same accompaniment key is operated, only the chord or root assigned to the operated accompaniment key can be played.
In the case of the electronic musical instrument which produces a rhythm backing by using a keyboard, the "KEY ON" operation must be effected each time a sound is to be generated, and thus great skill is required when operating the keys to produce even a basic rhythm backing. Namely, it is not easy to provide the rhythm backing.
In the case of the electronic musical instrument which automatically performs a melody, the performance of the melody is automatically started when a start switch is operated, and thereafter, the player cannot change the preset performance of the melody until that performance is finished.
The present invention is intended to obviate the above described drawbacks of the prior art electronic musical instruments.
Accordingly, an object of the present invention is to provide a motif performing apparatus by which an accompaniment can be changed by only depressing an accompaniment key and a rhythm backing can be easily played, and further, an automatic accompaniment can be effected simultaneously with a player's performance of a piece of music.